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Biomedical subjects

V Panichelli

Publications and source records attributed to V Panichelli.

6 recordsLinked to original sources

Toward a quantitative analysis of skin lesion images.

Melanoma is the most dangerous form of skin cancer. Skin cancers, and particularly melanomas, can be easily cured if detected early. The regularity of the pigment network structure is a significant sign for early diagnosis of melanoma. We present here a quantitative analysis of the morphology of the pigment network structure. Our method is based on the extraction of the pigment network structure using digital image processing techniques. Once the network is extracted, it is possible to derive statistical indicators relative to its regularity or irregularity. We report experiments on a database of 14 images, showing the effectiveness of our method.

Diagnostic Imaging↗

Electron arc therapy treatment planning verification with alanine/EPR dosimetry.

Alanine/EPR dosimetry was applied to measure dose distributions during electron arc therapy treatments generated by electron beams moving isocentrically over a stated arc. Alanine-polyethylene pellets, prepared at ISS according to the NIST recipe, inserted in a homogeneous cylindrical and anthropomorphic phantoms, were used. Preliminary, alanine response to static electron beams in the (6-20) MeV nominal energy range was studied. Then alanine dosimetry was applied to determine the dose versus the gantry angle at a reference point in a cylindrical homogeneous phantom. Finally, arc therapy treatment planning verification was performed in anthropomorphic phantom.

Alanine↗

[Role of high-definition and high frequency ultrasonography in determining tumor thickness in cutaneous malignant melanoma].

PURPOSE: We investigated the predictive capabilities of high frequency, high resolution ultrasound (US) in the preoperative assessment of tumor thickness in cutaneous malignant melanomas. This evaluation is a valuable help for correct surgical planning. MATERIAL AND METHODS: December 1997 to August 1998, we studied with US over 120 pigmented skin lesions and collected the data, including the final histologic diagnosis, of 78 of them, which make our series. Sixty-six of 78 lesions were histologically defined as cutaneous malignant melanomas with superficial spread and the other 12 as melanocytic nevi. All examinations were carried out with an Esaotebiomedica AU 5 Harmonic scanner equipped with a 20-MHz annular array probe and a linear 13-MHz probe; B-mode, color and power Doppler images were always acquired. RESULTS: The statistical analysis of the comparative US and histologic measurements of tumor thickness showed very good agreement, with a high Pearson's coefficient (R: .93). However, US frequently underestimated the actual thickness relative to histology, which is in contradiction with previous literature reports. We could study with US the melanoma in situ, which has never been described before. Last but not least, low-thickness melanomas had very few color and power Doppler signals. CONCLUSIONS: US is the correct tool for the preoperative assessment of the thickness of cutaneous malignant melanomas because it provides high agreement with histologic data even in lesions thinner than 1 mm.

Female↗

[Intraoperative radiotherapy with electrons (IORT). Dosimetry problems, first experience].

In this paper, preliminary results on the IORT dosimetry performed on the two radiotherapy centers, "Regina Elena National Cancer Institute" and "S. Cuore Catholic University", are presented. The absolute dosimetry has been performed with ion chambers (ENEA chamber and Markus flat chamber) using a water phantom. The relative measurements have been performed with solid state diodes and radiographic films, calibrated on absolute dosimetry system.

Combined Modality Therapy↗

Stereotactic irradiation therapy. Physical and dosimetric problems.

In stereotactic irradiation by external beams there are many problems involved with dosimetry of small fields, three-dimensional representation of dose distribution, radiobiological involvement of tissue response to total dose and fractionation. Dosimetric problems arise by critical dimension of dosimetric chambers and by difficulties of films calibration. The amount of data required for a correct three-dimensional simulation of isodose curves, tumor and anatomical structures require a very speed computer system, sophisticated computer graphic techniques and calculation algorithm. By use the linear quadratic model of cell survival, maps of combined dose and biological effect (isoeffect curves) are also obtained.

Brain Neoplasms↗